.. SPDX-License-Identifier: CC-BY-SA-4.0 .. Copyright (C) 2016 Chris Johns .. _rtems-kernel: RTEMS Kernel ============ RTEMS is an open source real-time operating system. As a user you have access to all the source code. The ``RTEMS Kernel`` section will show you how you build the RTEMS kernel on your host. Development Sources ------------------- Create a new location to build the RTEMS kernel: .. code-block:: none $ cd $HOME/development/rtems $ mkdir src $ cd src Clone the RTEMS respository: .. code-block:: none $ git clone git://git.rtems.org/rtems.git rtems Cloning into 'rtems'... remote: Counting objects: 483342, done. remote: Compressing objects: 100% (88974/88974), done. remote: Total 483342 (delta 390053), reused 475669 (delta 383809) Receiving objects: 100% (483342/483342), 69.88 MiB | 1.37 MiB/s, done. Resolving deltas: 100% (390053/390053), done. Checking connectivity... done. Building a BSP -------------- We build RTEMS in a directory within the source tree we have just cloned. For the details, see the :ref:`BSPBuildSystem`. We will build for the ``erc32`` BSP with POSIX enabled. Firstly, create the file :file:`config.ini` in the source tree root directory with the BSP build configuration, for example: .. code-block:: ini [sparc/erc32] RTEMS_POSIX_API = True Configure RTEMS using the ``waf configure`` command: .. code-block:: none $ cd $HOME/development/rtems/src/rtems $ ./waf configure --prefix=$HOME/development/rtems/6 Setting top to : $HOME/development/rtems/src/rtems Setting out to : $HOME/development/rtems/src/rtems/build Regenerate build specification cache (needs a couple of seconds)... Configure board support package (BSP) : sparc/erc32 Checking for program 'sparc-rtems6-gcc' : $HOME/development/rtems/6/bin/sparc-rtems6-gcc Checking for program 'sparc-rtems6-g++' : $HOME/development/rtems/6/bin/sparc-rtems6-g++ Checking for program 'sparc-rtems6-ar' : $HOME/development/rtems/6/bin/sparc-rtems6-ar Checking for program 'sparc-rtems6-ld' : $HOME/development/rtems/6/bin/sparc-rtems6-ld Checking for program 'ar' : $HOME/development/rtems/6/bin/sparc-rtems6-ar Checking for program 'g++, c++' : $HOME/development/rtems/6/bin/sparc-rtems6-g++ Checking for program 'ar' : $HOME/development/rtems/6/bin/sparc-rtems6-ar Checking for program 'gas, gcc' : $HOME/development/rtems/6/bin/sparc-rtems6-gcc Checking for program 'ar' : $HOME/development/rtems/6/bin/sparc-rtems6-ar Checking for program 'gcc, cc' : $HOME/development/rtems/6/bin/sparc-rtems6-gcc Checking for program 'ar' : $HOME/development/rtems/6/bin/sparc-rtems6-ar Checking for asm flags '-MMD' : yes Checking for c flags '-MMD' : yes Checking for cxx flags '-MMD' : yes Checking for program 'rtems-bin2c' : $HOME/development/rtems/6/bin/rtems-bin2c Checking for program 'gzip' : /usr/bin/gzip Checking for program 'xz' : /usr/bin/xz Checking for program 'rtems-ld' : $HOME/development/rtems/6/bin/rtems-ld Checking for program 'rtems-syms' : $HOME/development/rtems/6/bin/rtems-syms Checking for program 'rtems-bin2c' : $HOME/development/rtems/6/bin/rtems-bin2c Checking for program 'gzip' : /usr/bin/gzip Checking for program 'xz' : /usr/bin/xz 'configure' finished successfully (7.996s) Build RTEMS: .. code-block:: none $ ./waf Waf: Entering directory `$HOME/development/rtems/src/rtems/build' Waf: Leaving directory `$HOME/development/rtems/src/rtems/build' 'build' finished successfully (0.051s) Waf: Entering directory `$HOME/development/rtems/src/rtems/build/sparc/erc32' [ 1/1524] Compiling bsps/shared/dev/serial/mc68681_reg2.c [ 2/1524] Compiling bsps/shared/dev/rtc/mc146818a_ioreg.c [ 3/1524] Compiling bsps/shared/dev/flash/am29lv160.c ... [1521/1524] Linking $HOME/development/rtems/src/rtems/build/sparc/erc32/libz.a [1522/1524] Linking $HOME/development/rtems/src/rtems/build/sparc/erc32/librtemscxx.a [1523/1524] Linking $HOME/development/rtems/src/rtems/build/sparc/erc32/testsuites/samples/paranoia.exe [1524/1524] Linking $HOME/development/rtems/src/rtems/build/sparc/erc32/libmghttpd.a Waf: Leaving directory `$HOME/development/rtems/src/rtems/build/sparc/erc32' 'build_sparc/erc32' finished successfully (4.894s) Installing A BSP ---------------- All that remains to be done is to install the kernel. Installing RTEMS copies the API headers and architecture specific libraries to a locaiton under the `prefix` you provide. You can install any number of BSPs under the same `prefix`. We recommend you have a separate `prefix` for different versions of RTEMS. Do not mix versions of RTEMS under the same `prefix`. Make installs RTEMS with the following command: .. code-block:: none $ ./waf install Waf: Entering directory `$HOME/development/rtems/src/rtems/build' Waf: Leaving directory `$HOME/development/rtems/src/rtems/build' 'install' finished successfully (0.074s) Waf: Entering directory `$HOME/development/rtems/src/rtems/build/sparc/erc32' + install $HOME/development/rtems/6/sparc-rtems6/erc32/lib/include/libchip/am29lv160.h (from bsps/include/libchip/am29lv160.h) + install $HOME/development/rtems/6/sparc-rtems6/erc32/lib/include/libchip/mc146818a.h (from bsps/include/libchip/mc146818a.h) + install $HOME/development/rtems/6/sparc-rtems6/erc32/lib/include/libchip/mc68681.h (from bsps/include/libchip/mc68681.h) ... + install $HOME/development/rtems/6/sparc-rtems6/erc32/lib/include/rtems/version.h (from cpukit/include/rtems/version.h) + install $HOME/development/rtems/6/sparc-rtems6/erc32/lib/include/rtems/vmeintr.h (from cpukit/include/rtems/vmeintr.h) + install $HOME/development/rtems/6/sparc-rtems6/erc32/lib/include/rtems/watchdogdrv.h (from cpukit/include/rtems/watchdogdrv.h) Waf: Leaving directory `$HOME/development/rtems/src/rtems/build/sparc/erc32' 'install_sparc/erc32' finished successfully (0.637s) Contributing Patches -------------------- RTEMS welcomes fixes to bugs and new features. The RTEMS Project likes to have bugs fixed against a ticket created on our :r:url:`devel`. Please raise a ticket if you have a bug. Any changes that are made can be tracked against the ticket. If you want to add a new a feature please post a message to :r:list:`devel` describing what you would like to implement. The RTEMS maintainer will help decide if the feature is in the best interest of the project. Not everything is and the maintainers need to evalulate how much effort it is to maintain the feature. Once accepted into the source tree it becomes the responsibility of the maintainers to keep the feature updated and working. Changes to the source tree are tracked using git. If you have not made changes and enter the source tree and enter a git status command you will see nothing has changed: .. code-block:: none $ cd $HOME/development/rtems/src/rtems $ git status On branch master Your branch is up-to-date with 'origin/master'. nothing to commit, working directory clean We will make a change to the source code. In this example I change the help message to the RTEMS shell's ``halt`` command. Running the same git status command reports: .. code-block:: none $ git status On branch master Your branch is up-to-date with 'origin/master'. Changes not staged for commit: (use "git add ..." to update what will be committed) (use "git checkout -- ..." to discard changes in working directory) modified: cpukit/libmisc/shell/main_halt.c no changes added to commit (use "git add" and/or "git commit -a") As an example I have a ticket open and the ticket number is 9876. I commit the change with the follow git command: .. code-block:: none $ git commit cpukit/libmisc/shell/main_halt.c An editor is opened and I enter my commit message. The first line is a title and the following lines form a body. My message is: .. code-block:: none shell: Add more help detail to the halt command. Closes #9876. # Please enter the commit message for your changes. Lines starting # with '#' will be ignored, and an empty message aborts the commit. # Explicit paths specified without -i or -o; assuming --only paths... # # Committer: Chris Johns # # On branch master # Your branch is up-to-date with 'origin/master'. # # Changes to be committed: # modified: cpukit/libmisc/shell/main_halt.c When you save and exit the editor git will report the commit's status: .. code-block:: none $ git commit cpukit/libmisc/shell/main_halt.c [master 9f44dc9] shell: Add more help detail to the halt command. 1 file changed, 1 insertion(+), 1 deletion(-) You can either email the patch to :r:list:`devel` with the following git command, and it is `minus one` on the command line: .. code-block:: none $ git send-email --to=devel@rtems.org -1 Or you can ask git to create a patch file using: .. code-block:: none $ git format-patch -1 0001-shell-Add-more-help-detail-to-the-halt-command.patch This patch can be attached to a ticket.